Method and Device for Plugging of a Subsea Well

Abstract

A method and a device are for plugging a submerged well in which a wellhead valve is arranged at the seabed. The method includes: moving a perforation tool into the well and perforating a first perforation in the wall of an inner casing; perforating a second perforation in the wall of the inner casing at a considerable distance from the first perforation; filling a casting substance into at least a portion of an annulus between the first perforation and the second perforation; placing a connection housing between the well and the wellhead valve; performing the first perforation through the pipe wall of at least the inner casing at a height level at which the perforation enables access to the wall of a borehole; setting a packer in the inner casing between the two perforations; connecting a stinger to the connection housing, the stinger communicating with the first perforation; circulating fluid through an annulus located outside the inner casing, between the first perforation and the second perforation to clean the annulus; and filling a casting substance into the inner casing below the packer and at least into a portion of the annulus between the first perforation and the second perforation.

1 . A method for plugging a subsea well in which a wellhead valve is arranged at the seabed, the method comprising:
 moving a perforation tool into the well and perforating a first perforation through the wall of an inner casing;   perforating a second perforation in the wall of the inner casing at a considerable distance from the first perforation;   filling a casting substance into at least a portion of an annulus in an area between the first perforation and the second perforation;   placing a connection housing between the well and the wellhead valve;   performing the first perforation in at least the wall of the inner casing at a height level at which the perforation enables access to the wall of a borehole;   setting a packer in the inner casing between the two perforations;   connecting a stinger to the connection housing, the stinger communicating with the first perforation;   circulating fluid through an annulus located outside the inner casing, between the first perforation and the second perforation to clean the annulus; and   filling a casting substance into the inner casing below the packer and at least into a portion of the annulus between the first perforation and the second perforation.   
     
     
         2 . A method in accordance with  claim 1 , further comprising removing the packer and the stinger. 
     
     
         3 . A plugging tool for plugging a subsea well in which a wellhead valve is arranged at the seabed, the tool comprising a connection housing which fits sealingly between the well and the wellhead valve, the connection housing being formed with a through-going axial bore, a first pipe bore extending from the outside of the connection housing into the bore, and a second pipe bore extending from the outside of the connection housing and communicating with the pipe bore of a casing, and a stinger detachably and sealingly positioned in the connection housing, the stinger communicating with the first pipe bore and with the first perforation, and the stinger including an external expandable packer. 
     
     
         4 . The plugging tool in accordance with  claim 3 , wherein at least one of the first pipe bore and the second pipe bore communicates with a vessel. 
     
     
         5 . The plugging tool in accordance with  claim 3 , wherein at least one of the first pipe bore and the second pipe bore is provided with a valve.